中文 Chinese

TerarkDB Tuning Guide

There are some best practices you should know about TerarkDB. We will add those information ASAP, meanwhile if you need help you can post an issue in this repository.

1. SSTable Size

SSTable size is controlled by 2 options:

• ColumnFamilyOptions::target_file_size_base
• ColumnFamilyOptions::target_file_size_multiplier

In most cases, you can keep TerarkDB's configuration as default, it will work just fine. But if you meet cases like these:

• Your record key is related to the insert time (mostly in time series DB).
• Your record value is ordered by time while inserting.

You may need to use a smaller SSTable size, since client users are likely to delete data that is in the same SSTable, which will frequently causes whole SSTable deletions.

2. Write triggers

config name	RocksDB default
level0_file_num_compaction_trigger	4
level0_slowdown_writes_trigger	20
level0_stop_writes_trigger	36

level0_file_num_compaction_trigger

Number of files to trigger level-0 compaction. A value <0 means that level-0 compaction will not be triggered by number of files at all.

level0_slowdown_writes_trigger and level0_stop_writes_trigger

TerarkDB is faster on read, and slower on write, we should pay read for write, so these 2 config for TerarkDB should be larger than RocksDB.